Similar composition of rat and human extraoccular muscles (EOM) qualify rat EOM as a suitable model for experimental studies on human EOM: muscle fibres were arranged in orbital and global layer, in which hybrid fibres co-expressing more MyHC isoforms prevailed. Slow, mostly oxidative fibres predominantly co-expressed MyHC-1 and –?, whereas fast fibres of various metabolic profile expressed various combinations of fast (2a, 2x, 2b), extraocular and developmental (emb, neo) isoforms. For the first time MyHC-2b and corresponding mRNA transcripts were demonstrated in human muscle.
COBISS.SI-ID: 26132953
Capillary supply of skeletal muscle cells is usually evaluated from two-dimensional (2D) images of thin transverse sections by counting the capillaries around a fibre (CAF). This 2D method is theoretically biased, because muscle cells are long spindle shaped and the supplying capillaries are tortuous. By comparing 2D and three-dimensional (3D) methods in the same samples of the true muscle tissue and in geometrical models of muscle fibres with different realistic capillary bed we proved that the 2D method is biased and can underestimate capillary length for up to 75%.
COBISS.SI-ID: 25594841
Description: Recent investigations suggest that the role of neural agrin might not be limited to neuromuscular junction formation and maintenance and that it might promote also other aspects of muscle development. Here we confirmed the hypothesis that agrin participates in the establishment of excitability of human myotubes. Agrin treatment increased Na+/K+ ATPase expression and its contribution in establishing the resting membrane potential and decreased apamin-sensitive K+ channels. These results are confirming the role of agrin as a general promoter of muscle development.
COBISS.SI-ID: 1505235
Nova1 and Nova2 are neuron-specific splicing factors and are essential regulators of Z agrin. Nova1/Nova2 double knockout mice are paralyzed and fail to cluster AChRs at the NMJ. Breeding them with transgenic mice constitutively expressing Z agrin in motor neurons rescued AChR clustering but mice remain paralyzed. These results point to a proximal defect in motor neuron firing in the absence of Nova and reveal a previously unsuspected role for RNA regulation in the physiologic activation of motor neurons.
COBISS.SI-ID: 25482201
Myopathies are often met at the organophosphate (OP) poisoning. Skeletal muscle responds to the injury by the activation of regeneration process which is basically a repeated embryonic muscle development. On the basis of original research of our group we describe in this chapter the effects of organophosphate compound DFP on muscle regeneration. Chapter is a part of a book by Elsevier written as a Handbook with the purpose to serve as a »golden standard« in the field of OP biological effects. The price of the book (used or new) on the Amazon.com is around 200 USD.
COBISS.SI-ID: 25500377